How about interracial marriage instead?
Double standards are appaling in this case.
I've just read Marco's http://www.marco.org/2014/04/04/political-views and I think he hits the nail on the head.
I don't find the comparison all that revealing. Clearly, there is no substantive difference between races. However, there are a few obvious substantive differences between genders, and these differences might lead one to a different belief regarding marriage. A belief in outlawing interracial marriage necessarily comes from hateful beliefs. A belief regarding gay marriage doesn't necessarily come from hate/homophobia.